The present application relates to a fiber optic gyroscope (FOG) and, in particular, to methods of making a spliceless FOG.
A FOG is a device that uses the propagation of light beams in an optical coil to detect mechanical rotation of the optical coil. The sensor is a coil with a length of as much as 5 km. The typical implementation provides that two light beams be launched into the optical coil in opposite directions. Due to an optical phenomenon known as the Sagnac effect, the beam traveling against the rotation experiences a slightly shorter path than the other beam resulting in a relative phase shift. The amount of the phase shift of the original two beams can be measured by determining how the beams interfere with each other when they are combined. The intensity of the combined beam then depends on the rotation rate of the fiber coil about its axis.
A FOG provides extremely precise rotational rate information, in view of its lack of cross-axis sensitivity to vibration, acceleration, and shock. Unlike the classic spinning-mass gyroscope, the FOG has virtually no moving parts and no inertial resistance to movement. The FOG also can provide higher resolution than a ring laser gyroscope and is utilized in inertial navigation systems requiring a very high degree of accuracy.